1. Field of the Invention
The present invention relates to an alkali-based treating liquid, a method and an equipment for adjusting the same, and a method and an equipment for supplying an alkali-based treating liquid. More specifically, the present invention relates to an alkali-based treating liquid for use in the development or formation with treatment of an organic film, such as a photoresist or a functional film, applied onto a substrate, a method and an equipment for adjusting this alkali-based treating liquid, and a method and an equipment for supplying the alkali-based treating liquid for the development of the photoresist, the treatment of the functional film or the like.
2. Description of the Related Art
In fields such as manufacturing of micro-devices and microfabrication (micromachining), various kinds of organic films are recently employed for different purposes. Typical examples of such organic films include thin films of organic photosensitive resin compositions called photoresists, which are essential to photolithography, and so-called functional organic films.
Photolithographic techniques are widely used for transferring micropatterns to wafers and other substrates in the manufacturing of semiconductor devices, such as memories and logical circuits, and liquid crystal devices. The photolithographic process is an essential part of the manufacturing processes of the above-described devices, and generally involves applying a thin film of photoresist onto a wafer, for example, by spin coating, and exposing the film through a mask with light, followed by development, thereby transferring the mask pattern to the wafer.
There are many different types of photoresists employed in such photolithographic processes, depending on the applications or requirements. Examples include positive and negative resists, i-line resists, and resists for KrF and ArF eximer lasers. These photoresists can also be classified, in terms of the materials used, into various types, including DQN resists containing the matrix material novolac (N; Novolac) resin and a diazoquinone (DQ)xe2x80x94based photosensitizer added thereto, resists containing a photo acid generator and chemically amplified resists. In the development of these photoresists (especially, the positive resists), alkali-based developing liquids, such as tetramethyl ammonium hydroxide (TMAH) aqueous solution and potassium hydroxide (KOH) aqueous solution, are widely employed.
Generally, in the lithographic process for the manufacturing of semiconductor devices and liquid crystal devices, the development is performed by applying an alkali-based developing liquid to an exposed photoresist by the spray method, paddle method, or dip method. In many cases, the developing liquid used in this process is not reused, that is, a fresh developing liquid is disposed of after one use. This tendency is particularly strong in the manufacturing of semiconductor devices.
Some of the possible reasons are as follows: (1) The amount used of the developing liquid per wafer is small, since the standard size for wafers currently used in the manufacturing of semiconductor devices is 8 inches (200 mm xcfx86); (2) The developing liquid is diluted with rinse water, so that the alkali concentration of the solution is decreased; (3) If the developing liquid is reused, the increase and accumulation of particles, metal ions and the like contained in the solution may have an undesirable effect during the following processes; and (4) The developing liquid is not necessarily controlled sufficiently in a manner suitable for each of the different applications and materials of photoresists and developing liquids described above.
Meanwhile, examples of the functional film include protective films for preventing the degradation and damage of liquid crystal display devices, semiconductor circuit devices and the like; smoothing films for smoothing surfaces of the devices; interlayer insulating films for insulating interconnects disposed in the form of layers; spacers for maintaining a constant interval between two substrates that seal the liquid crystal of a liquid crystal panel; liquid crystal alignment films capable of aligning liquid crystals; light scattering films for achieving a high front brightness for semi-transparent and reflective liquid crystal displays; and low dielectric constant films having low dielectric constants. Examples of the functional organic film include microlenses serving as optical devices. These functional films have superior properties according to their applications, such as electrical insulation, flatness, heat resistance, transparency, chemical resistance and mechanical strength.
In general, these functional films are each composed mainly of an alkali-soluble organic resin. Like photoresists, functional films can be classified roughly into positive and negative types, and the lithographic process is frequently used for the formation treatment of the films. The lithographic process used in the manufacturing of the functional films also involves applying an alkali-based treating liquid onto an exposed functional film by the spray method, paddle method, or dip method. Usually, the treating liquid used in this process is not reused, and, in many cases, a fresh treating liquid is disposed of after one use.
In recent years, further miniaturization has been accelerating for semiconductor devices, liquid crystal devices, micro-components such as micromachines and the like. In particular, the miniaturization of semiconductor devices, along with the reduction in layer thickness thereof, has been proceeding at a rapid pace that is unexpected from conventional design rules. For instance, the manufacturing of semiconductor memory products by a 0.13 xcexcm process is already underway, and the photolithography thus plays an increasingly important role in the manufacturing process. Accordingly, it is required to reliably achieve finer line widths than ever in the patterning of photoresists. Under such circumstances, in order to prevent yield loss, it is necessary to further reduce particles and the like entering the developing liquid. For this reason, the developing liquid may continue to be disposed of after one use.
At the same time, an increase in wafer size has also been promoted for increased productivity, along with the miniaturization and the reduction in layer thickness. Accordingly, 300 mmxcfx86 wafers produced by single wafer processing are expected to soon become the standard. This will increase the amounts of developing liquid and rinse water to be used, leading to an increase in material cost and in the amounts of liquid wastes of the developing liquid and rinse water to be generated and treated. In addition to the foregoing, the inventors of the present invention acquired the following findings as a result of in-depth research on the conventional photoresist (positive resist) development process employing a fresh developing liquid.
In general, a photoresist applied onto a wafer is pre-baked to be fixed, and is then exposed and developed. In the case of the positive resist, the functional group in the exposed portion is converted to carboxylic acid or other chemical form that reacts readily with alkali, so that the dissolution rate of the exposed portion of the resist in an alkali-based developing liquid becomes significantly higher than that of the unexposed portion. Here, a positive resist is applied onto a metal thin film formed on a wafer, and then, after the photoresist is exposed and developed to perform patterning, the metal thin film is etched. In this case, the metal thin film is etched in the portion exposed under the exposed portion of the photoresist that has been dissolved in the development process.
However, it was found that, under certain conditions, poor etching could occur in the above-described portion of the metal thin film. Such poor etching either reduces the conductivity and results in lower product reliability, or causes conduction failure leading to defective products, thereby decreasing yield. Moreover, with the miniaturization of semiconductor devices and liquid crystal devices and the reduction in layer thickness thereof, this phenomenon may occur with a higher probability, resulting in a decrease in productivity.
The inventors of the present invention conducted further research on the cause of the poor etching. As a result, the inventors of the present invention found that, either in the post-baking or hard-baking after the development process, or in the rinsing step, the surface layer or surface of the photoresist remaining on the wafer peels off and the peeled pieces adhere onto the exposed metal thin film, which is one factor of impeding the etching. Furthermore, if the above-described phenomenon has something to do with the solubility of the developing liquid, not only the exposed portion, but also the unexposed portion may not be sufficiently dissolved by the conventional photoresist development method employing a fresh liquid. In order to achieve finer pattern line widths, there is a demand for further improvement in the solubility and the selective solubility of the developing liquid in the development process.
Furthermore, a problem similar to the poor etching in the development process of photoresists as described above may also occur in the formation or formation treatment of functional films. That is, when treating an exposed functional film with an alkali-based treating liquid, poor treatment may result in the same manner as in the case of the poor etching that may result in the photoresist.
In view of the foregoing problems, it is an object of the present invention to provide an alkali-based treating liquid for use in the development or treatment of an organic film, such as a photoresist or a functional film, applied onto a substrate, that is capable of reducing the amount of the alkali-based treating liquid used and the amount of liquid waste produced, has excellent solubility with respect to an exposed organic film, and is capable of sufficiently preventing poor development and poor treatment, such as the peeling of the surface layer of the organic film. It is another object of the present invention to provide a method and an equipment for adjusting the alkali-based treating liquid, and a method and an equipment for supplying the alkali-based treating liquid to the processes and facilities in which the development or treatment is performed.
In order to solve the above problems, the inventors of the present invention conducted in-depth research based on the above findings, and found that a slightly soluble film exhibiting dissolution-resistance against an alkali-based developing liquid is formed in the surface layer of an unexposed portion of a positive photoresist, and this film portion is peeled from an underlying layer thermally or mechanically in a post baking or rinse process after development, and thus the surface layer peels off. It is also found that the permeability of the alkali-based developing liquid to the photoresist is one factor that affects the solubility of the resist, and in particular, it can affect significantly the initial solubility of the photoresist on which surface the slightly soluble film is formed.
Moreover, it was confirmed that this phenomenon is also seen in the formation and treatment of a functional film such as a protective film, a smoothing film, an interlayer insulating film, a spacer between substrates, a liquid crystal alignment film, a light scattering film, a low dielectric constant film, and a microlens.
The inventors of the present invention further proceeded with the research based on the above findings and achieved the present invention.
More specifically, the present invention is an alkali-based treating liquid for use in development treatment of a photoresist applied onto a substrate or formation treatment of the above-described various organic functional films, that is, for use in treating a photosensitive organic film, and is characterized in that a first component (organic film component) constituting an organic film of the same type as or a different type from the organic film to be treated is dissolved in a concentration of 0.001 to 2.0 mass %.
Thus, the alkali-based treating liquid of the present invention contains a certain concentration of the first component (dissolved organic film component) dissolved as a constituent component. This alkali-based treating liquid containing the first component has a significantly higher wettability with respect to an exposed organic film applied on a wafer than that of prior art employing a fresh liquid. More specifically, it was confirmed that the surface tension of the alkali-based treating liquid on the organic film was reduced significantly. Thus, the alkali-based treating liquid can permeate readily into the surface of the organic film, and be easily absorbed therein.
In particular, in the example of the photoresist described above, the alkali-based treating liquid (alkali-based developing liquid in this case) is sufficiently absorbed also into the slightly soluble film in an unexposed portion, so that the dissolution of the slightly soluble film is facilitated. It is preferable that the first component dissolved has a similar composition to that of the organic film to be treated, more preferably the same or substantially the same composition of the organic film to be treated, because the wettability of the alkali-based treating liquid and the organic film is further increased, which facilitates the permeation. Further more, it is desirable that the alkali-based treating liquid contains the same type of matrix and/or photosensitizer as the organic film to be treated.
When the concentration of the first component dissolved is less than 0.001 mass %, the permeability of the alkali-based treating liquid to the organic film is not sufficiently increased, and an advantage over a conventional fresh liquid can be hardly provided. On the other hand, when the concentration of the first component exceeds 2.0 mass %, erosion (edge effect) may be significant in an edge portion on the upper surface of the organic film remaining as a pattern (corresponding to an unexposed portion in the positive type), and the following processes such as etching of the underlying layer and film formation may be adversely affected, and therefore this range is not preferable. When the concentration of the first component dissolved exceeds 2.0 mass %, the permeability corresponding to the concentration is hardly exhibited. In this specification, the component concentration contained in the alkali-based treating liquid is defined on the mass basis, that is, xe2x80x9cmass %xe2x80x9d, which is substantially equal to xe2x80x9cweight %xe2x80x9d, that is, the weight basis (which also applies to the following).
It is preferable that when the organic film is a photoresist and the treatment is a development, a second component, serving as the first component, constituting an organic film of the same type as or different type from the photoresist to be developed is dissolved in a concentration of 0.001 to 2.0 mass %, preferably 0.01 to 1.5 mass %, and more preferably 0.1 to 1.0 mass %. When the second component is a photoresist component of the same type as or a different type from the photoresist to be developed, the second component substantially becomes the photoresist component. The second component may be an organic film component other than the photoresist component, for example, a functional film component as described later.
In this case, the alkali-based treating liquid functions as an alkali-based developing liquid containing the second component dissolved as a constituent component in the above-described concentration. This alkali-based treating liquid containing the second component dissolved has a significantly higher wettability with respect to an exposed organic film applied on a wafer than that of prior art employing a fresh liquid. This seems to be because the surface tension of the alkali-based treating liquid on the photoresist is reduced significantly, and the alkali-based treating liquid can permeate readily into the surface of the photoresist.
It is preferable that the second component dissolved has a similar composition to that of the photoresist to be developed, more preferably the same or substantially the same composition of the photoresist to be developed, because the wettability of the alkali-based treating liquid and the photoresist is further increased, which facilitates the permeation. Furthermore, it is further desirable that the alkali-based treating liquid contains the same type of matrix and/or photosensitizer as the photoresist to be developed.
When the concentration of the second component dissolved is less than 0.001 mass %, the permeability of the alkali-based treating liquid to the photo resist is not sufficiently increased, and an advantage over a conventional fresh liquid can be hardly provided. On the other hand, when this concentration exceeds 2.0 mass %, erosion (edge effect) may be significant in an edge portion on the upper surface of the photoresist remaining as a pattern (corresponding to the unexposed portion in the positive type and the exposed portion in the negative type), and the following processes such as etching of the underlying layer and film formation may be adversely affected, and therefore this range is not preferable. When the concentration of the second component exceeds 2.0 mass %, the permeability corresponding to the concentration is hardly exhibited.
Alternatively, it is also useful that when the organic film is a functional film, a third component (functional film component), serving as the first component, constituting an organic film of the same type as or a different type from the functional film to be treated is dissolved in a concentration of preferably 0.001 to 0.5 mass %, more preferably 0.01 to 0.3 mass %. When the third component is a functional film component of the same type as or a different type from the functional film to be treated, the third component substantially becomes the functional film component. The third component may be an organic film component other than the functional film component, for example, the photoresist component as described above.
Hereinafter, the xe2x80x9cfunctional filmxe2x80x9d of the present invention will be described. The functional film is a sort of a permanent film that contains a photosensitive organic polymer resin as the main component, can be treated to a desired patterning geometry by the alkali treating liquid, and can stay in a substrate as a structural element without being subjected to a stripping process thereafter to carry out various required functions. On the other hand, the photoresist serves as a resist (resistive film) for patterning by etching of a metal thin film or a metal oxide thin film on a substrate, and is removed by resist stripping after etching, and eventually does not exist on the substrate, that is, a provisional film that is temporarily used.
Examples of positive type functional films of such functional films include films made of a solution of the following substances as the raw material: alkali soluble organic resins (unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, epoxy group-containing unsaturated compounds, resins containing copolymers of olefin based unsaturated compounds or the like, resins containing alkali soluble cyclic polyolefin based resins, etc.), solvents, or 1,2-quinone diazide compounds serving as a photosensitizer.
After this raw solution is applied onto a substrate, the substrate is prebaked so that the solvent is volatilized, and a positive type photosensitive coating film is formed.
Then, the film is exposed to ultraviolet rays via a mask having a predetermined shape or the like, and thereafter the exposed portion is dissolved in the alkali-based treating liquid of the present invention. The substrate with the remaining unexposed portion is post-baked, and thus a functional film having a predetermined pattern is obtained.
Examples of negative type functional films include films made of a solution of the following substances as the raw material: alkali soluble organic resins (unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, epoxy group-containing unsaturated compounds, resins containing copolymers of olefin based unsaturated compounds or the like), polymeric compounds having an ethylene unsaturated bond, solvents, or radiation-sensitive polymerization initiator.
After this raw solution is applied onto a substrate, the substrate is prebaked so that the solvent is volatilized, and a negative type photosensitive coating film is formed. Then, the film is exposed to ultraviolet rays via a mask having a predetermined shape or the like, and thereafter the unexposed portion is dissolved in the alkali-based treating liquid of the present invention. The substrate with the remaining exposed portion is post-baked, and thus a functional film having a predetermined pattern is obtained.
With respect to such a functional film, the alkali-based treating liquid functions as an alkali-based formation treating liquid containing the third component (dissolved functional film component) dissolved as a constituent component in the above-described concentration. This alkali-based treating liquid containing the third component dissolved has a significantly higher wettability with respect to an exposed organic film applied on a wafer than that of prior art employing a fresh liquid. This seems to be because the surface tension of the alkali-based treating liquid on the functional film is reduced significantly, and the alkali-based treating liquid can permeate readily into the surface of the functional film.
It is preferable that the third component dissolved has a similar composition to that of the functional film to be treated, more preferably the same or substantially the same composition of the functional film to be treated, because the wettability of the alkali-based treating liquid and the functional film is further increased, which facilitates the permeation. Furthermore, it is desirable that the alkali-based treating liquid contains the same type of matrix and/or photosensitizer as the functional film to be treated.
When the concentration of the third component dissolved is less than 0.001 mass %, the permeability of the alkali-based treating liquid is not sufficiently increased, and an advantage over a conventional fresh liquid can be hardly provided. On the other hand, when the concentration of the third component exceeds 0.5 mass %, erosion may be significant in an edge portion on the upper surface of the functional film remaining as a pattern (corresponding to the unexposed portion in the positive type and the exposed portion in the negative type), and a desired pattern cannot be obtained, and therefore this range is not preferable.
Alternatively, the alkali component in the alkali-based treating liquid is a principle factor that affects the solubility of the organic film, and more specifically, it is preferable that the alkali component is contained in a concentration of 0.05 to 2.5 mass %. In such a preferable range, the concentration can be controlled as appropriate, in accordance with the type of the organic film to be treated and/or the alkali.
Furthermore, when the organic film is a photoresist, it is preferable that the alkali component is contained in a concentration of preferably 0.1 to 2.5 mass %, and more preferably 0.1 to 2.4 mass %.
More specifically, for example, for an alkali-based developing liquid for photoresists for use in the manufacturing of semiconductor devices, it is useful that the alkali component (e.g., TMAH) is contained preferably in 2.2 to 2.4 mass %, more preferably 2.3 to 2.4 mass %. For an alkali-based developing liquid for photoresists (e.g., DQN resist) for use in the manufacturing of liquid crystal devices, it is useful that the alkali component is contained preferably in 2.2 to 2.4 mass %, and more preferably 2.3 to 2.4 mass %.
When the concentration of the alkali component is less than 0.1 mass %, the rate of dissolution of the photoresist tends to be reduced to an degree that is insufficient in practical use. On the other hand, when the concentration of the alkali component is more than 2.5 mass %, the solubility corresponding to an increase of the concentration cannot be obtained, and in some cases, this concentration makes it difficult to control the solubility of the photoresist and patterning geometry.
Alternatively, when the organic film is a functional film, it is preferable that the alkali component in the alkali-based treating liquid is contained in a concentration of preferably 0.05 to 2.4 mass %, and more preferably 0.08 to 2.4 mass %.
More specifically, for example, for the alkali-based treating liquid for a negative type (meth) acrylic functional film that is preferably used as a protective film and a spacer, it is useful that the concentration of the alkali component (e.g., TMAH) is preferably 0.05 to 0.6 mass %, and more preferably 0.08 to 0.12 mass %. For the alkali-based treating liquid for a positive type (meth) acrylic functional film that is preferably used as a protective film or an interlayer insulating film and a spacer, the concentration of the alkali component (e.g., TMAH) is preferably 0.05 to 0.6 mass %, and more preferably 0.1 to 0.3 mass %.
For the alkali-based treating liquid for a negative type (meth) acrylic functional film that is preferably used as a protective film and a liquid crystal alignment film, it is useful that the concentration of the alkali component (e.g., TMAH) is preferably 0.05 to 0.6 mass %, and more preferably 0.3 to 0.6 mass %. For the alkali-based treating liquid for a positive type epoxy based functional film that is preferably used as a microlens, it is useful that the concentration of the alkali component (e.g., TMAH) is preferably 0.5 to 2.4 mass %, and more preferably 1.0 to 2.4 mass %. For the alkali-based treating liquid for a negative type (meth)acrylic functional film that is preferably used as an interlayer insulating film, it is useful that the concentration of the alkali component (e.g., TMAH) is preferably 1.0 to 2.4 mass %, and more preferably 2.3 to 2.4 mass %.
When the concentration of the alkali component is less than 0.05 mass %, the rate of dissolution of the functional film tends to be reduced to an degree that is insufficient in practical use. On the other hand, when the concentration of the alkali component is more than 2.4 mass %, the solubility corresponding to an increase of the concentration cannot be obtained, and in some cases, this concentration makes it difficult to control the solubility of the functional film and patterning geometry.
In another aspect, a method for adjusting an alkali-based treating liquid of the present invention is a method for efficiently adjusting the alkali-based treating liquid of the present invention and a method for adjusting the alkali-based treating liquid for use in a process for treating (or processing) an organic film applied onto a substrate, and is characterized in that the alkalinity of the alkali-based treating liquid is adjusted such that the concentration of a first component (dissolved organic film component) contained in the alkali-based treating liquid and constituting an organic film of a same type as or different type from the organic film to be treated is in the range of 0.001 to 2.0 mass %, and the concentration of an alkali component contained in the alkali-based treating liquid is in the range of 0.05 to 2.5 mass %.
More specifically, for example, the concentrations of the first component dissolved and the alkali component contained in the alkali-based treating liquid are measured when appropriate, and based on respective actually measured values and preset concentration values, the following operation can be performed manually or automatically, when appropriate: when the actually measured values do not reach the desired preset values, the first component or alkali is added and dissolved, whereas when the actually measured values exceeds the desired preset values, the alkali-based treating liquid is diluted. Alternatively, the amounts of the alkali and the photoresist added to and dissolved in a solvent of the alkali-based treating liquid may be measured and controlled.
Furthermore, it is preferable that when the organic film is a photoresist and the treatment is a development, the alkalinity of the alkali-based treating liquid is adjusted such that the concentration of a second component, serving as the first component, contained in the alkali-based treating liquid and constituting an organic film of the same type as or a different type from the photoresist to be developed is in the range of 0.001 to 2.0 mass %, and the concentration of an alkali component contained in the alkali-based treating liquid is in the range of 0.1 to 2.5 mass %.
More specifically, for example, the concentrations of the second component dissolved and the alkali component contained in the alkali-based treating liquid are measured when appropriate, and based on respective actually measured values and preset concentration values, the following operation can be performed manually or automatically, when appropriate: when the actually measured values do not reach the desired preset values, the second component or alkali is added and dissolved, whereas when the actually measured values exceeds the desired preset values, the alkali-based treating liquid is diluted. Alternatively, the amounts of the alkali and the second component added to and dissolved in a solvent of the alkali-based treating liquid may be measured and controlled.
Alternatively, it is preferable that when the organic film is a functional film, the alkalinity of the alkali-based treating liquid is adjusted such that the concentration of a third component, serving as the first component, contained in the alkali-based treating liquid and constituting an organic film of the same type as or a different type from the functional film to be treated is in the range of 0.001 to 0.5 mass %, and the concentration of an alkali component contained in the alkali-based treating liquid is in the range of 0.05 to 2.4 mass %.
More specifically, for example, the concentrations of the third component dissolved and the alkali component contained in the alkali-based treating liquid are measured when appropriate, and based on respective actually measured values and preset concentration values, the following operation can be performed manually or automatically, when appropriate: when the actually measured values do not reach the desired preset values, the third component or alkali is added and dissolved, whereas when the actually measured values exceeds the desired preset values, the alkali-based treating liquid is diluted. Alternatively, the amounts of the alkali and the third component added to and dissolved in a solvent of the alkali-based treating liquid may be measured and controlled.
In another aspect, a method for supplying an alkali-based treating liquid of the present invention is a method for supplying the alkali-based treating liquid adjusted according to the present invention to a treating process of an organic film applied onto a substrate, and includes (1) the receiving step of receiving a used liquid containing a first component (organic film component) constituting an organic film of a same type as or different type from the organic film; (2) the concentration measuring step of measuring concentrations of the first component (dissolved organic film component) and an alkali component contained in the used liquid; (3) the adjusting step of adjusting the alkalinity of the used liquid, based on the actually measured concentration values of the first component and the alkali component, such that the concentration of the first component contained in the used liquid is in the range of 0.001 to 2.0 mass %, and the concentration of the alkali component contained in the used liquid is in the range of 0.05 to 2.5 mass %, thereby producing a regenerated liquid; and (4) the supplying step of supplying the regenerated liquid to the treating process. The used liquid that is received in the receiving step can be a liquid that has been supplied in the supplying step and used in the treating step, or a liquid that has been used in another facility.
The used liquid received in the receiving step has been subjected to a treatment of, for example, an organic film and contains the first component dissolved or dispersed therein, and generally has been diluted with rinse water so that the content of the alkali component becomes smaller than that in the early stage. In the concentration measuring step, the concentrations of the first component dissolved and the alkali component contained in this used liquid are measured. Then, in the adjusting step, these actually measured values are compared with, for example, the preset concentration values. When they are insufficient, the first component and/or the alkali are supplemented in accordance with the difference, whereas when they are excessive, the liquid is diluted as appropriate. In this case, it is preferable to perform the concentration measuring step and the adjusting step continuously in parallel and perform feedback control of the concentrations. Then, a regenerated liquid whose concentrations of the first component dissolved and the alkali component are adjusted to be in the above-described predetermined ranges is supplied to a treating step of an organic film.
It is preferable that when the organic film is a photoresist and the treatment is a development, the alkalinity of the used liquid is adjusted, such that the concentration of the second component, serving as the first component, contained in the alkali-based treating liquid and constituting an organic film of the same type as or different type from the photoresist to be developed is in the range of 0.001 to 2.0 mass %, and the concentration of an alkali component contained in the alkali-based treating liquid is in the range of 0.1 to 2.5 mass %. In this case, a regenerated liquid containing the second component and the alkali component in the above-described ranges is supplied to a developing step of the photoresist.
Alternatively, it is preferable that when the organic film is a functional film, the alkalinity of the alkali-based treating liquid is adjusted such that the concentration of the third component, serving as the first component, contained in the alkali-based treating liquid and constituting an organic film of the same type as or different type from the functional film to be treated is in the range of 0.001 to 0.5 mass %, and the concentration of an alkali component contained in the alkali-based treating liquid is in the range of 0.05 to 2.4 mass %. In this case, a regenerated liquid containing the third component and the alkali component in the above-described ranges is supplied to a treating step of the functional film.
Furthermore, it is preferable that the method includes (5) a pre-treating step performed between the receiving step and the adjusting step, including at least one step selected from the group consisting of the filtrating step of filtrating the used liquid; the residual component removing step of removing the first component (or the second component or the third component) that remains in the used liquid; and the metal component removing step of removing a metal component contained in the used liquid:
When a liquid that has been used for a treatment of an organic film is used as the used liquid, the first component may remain in the form of being dispersed, dissolved, or residue in some cases, etc., and furthermore the liquid may contain metal ions or the like that are dissolved in the course of being supplied to the receiving step. It is necessary to prevent contamination of these substances in the manufacturing of devices such as semiconductor devices and liquid crystal devices or micromachining thereof, and therefore it is preferable to perform the filtrating step and the metal component removing step. The used liquid may contain the first component dissolved in a concentration of more than 2.0 mass %, that is, the upper limit of the above predetermined range, and it is preferable to perform the residual component removing step to remove a certain amount of the first component before the adjusting step.
It is preferable that in the filtrating step, the used liquid is filtrated into a permeated liquid and an unpermeated liquid by cross flow filtration, and the adjusting step includes an unpermeated liquid adding step of adding the unpermeated liquid to the used liquid. Herein, the xe2x80x9cpermeated liquidxe2x80x9d generally refers to components (permeated components) that have permeated filtrating means in filtration and is constituted mainly or substantially by liquid components. The xe2x80x9cunpermeated liquidxe2x80x9d generally refers to components (unpermeated components) that have not permeated the filtrating means in filtration. In other words, the unpermeated liquid represents the portion other than the xe2x80x9cpermeated liquidxe2x80x9d of the used liquid and is constituted mainly or substantially by liquid components, although the unpermeated liquid may have a solid content as residue of the filtration, depending on the characteristics of the used liquid.
There is no particular limitation on the filtrating means, but cross flow filtration is preferable in view of filtration precision (particle or molecular weight size) preferable to the cleanliness, the clarity, the particle density, etc. of the alkali-based treating liquid required for manufacturing of devices such as semiconductor devices and liquid crystal devices. In this case, the used liquid is filtrated into an unpermeated liquid containing substances of the fraction size (filtration size) or larger and a permeated liquid containing substances smaller than the fraction size.
The unpermeated liquid contains the first component, i.e., organic component of the fraction size or larger, or the second component or the third component, and if this unpermeated liquid is added to the used liquid in the unpermeated liquid adding step, it can be used to adjust the concentration of the first, second and third components dissolved in the used liquid. Therefore, it is not necessary to separately supplement fresh first, second and third components in the adjusting step. If the filtration size is set as appropriate in the filtrating step, metal ions in the unpermeated liquid can be reduced sufficiently, so that this is preferable for adjustment of the concentrations in the adjusting step.
It is further preferable to include (6) a post-treating step performed between the adjusting step and the supplying step, including a particle removing step of removing a particle component from the regenerated liquid, because contamination of particles in the treating process can be prevented.
In another aspect, a treating liquid adjusting equipment of the present invention is an equipment for adjusting an alkali-based treating liquid for use in treating an organic film applied onto a substrate and includes an adjusting portion for adjusting the alkalinity of the alkali-based treating liquid such that the concentration of a first component (dissolved organic film component) contained in the alkali-based treating liquid and constituting an organic film of the same type as or a different type from the organic film is in the range of 0.001 to 2.0 mass %, and the concentration of an alkali component contained in the alkali-based treating liquid is in the range of 0.05 to 2.5 mass %.
It is preferable that when the organic film is a photoresist and the treatment is a development, the adjusting portion adjusts the alkalinity of the alkali-based treating liquid such that the concentration of a second component, serving as the first component, contained in the alkali-based treating liquid and constituting an organic film of the same type or a different type from the photoresist to be developed is in the range of 0.001 to 2.0 mass %, and the concentration of an alkali component contained in the alkali-based treating liquid is in the range of 0.1 to 2.5 mass %.
Alternatively, it is also preferable that when the organic film is a functional film, the adjusting portion adjusts the alkalinity of the alkali-based treating liquid such that the concentration of a third component, serving as the first component, contained in the alkali-based treating liquid and constituting an organic film of the same type as or different type from the functional film to be treated is in the range of 0.001 to 0.5 mass %, and the concentration of an alkali component contained in the alkali-based treating liquid is in a range of 0.05 to 2.4 mass %.
In another aspect, an alkali-based developing liquid supplying equipment of the present invention is an equipment for supplying an alkali-based treating liquid to a treating portion of an organic film applied onto a substrate includes (a) a receiving portion to which a used liquid containing a first component (dissolved organic film component) constituting an organic film of a same type as or different type from the organic film is supplied; (b) a concentration measuring portion for measuring concentrations of the first component and an alkali component contained in the used liquid; (c) an adjusting portion for adjusting the alkalinity of the used liquid, based on the actually measured concentration values of the first component and the alkali component, such that the concentration of the first component contained in the used liquid is in the range of 0.001 to 2.0 mass %, and the concentration of the alkali component contained in the used liquid is in the range of 0.05 to 2.5 mass %, thereby producing a regenerated liquid; and (d) a supplying portion for supplying the regenerated liquid to the treating portion.
Furthermore, it is preferable that when the organic film is a photoresist, the receiving portion receives a used liquid containing a second component constituting an organic film of the same type or a different type from the photoresist as the used liquid; the concentration measuring portion measures concentrations of the second component and an alkali component contained in the used liquid; and the adjusting portion adjusts an alkalinity of the used liquid, based on the actually measured concentration values of the second component and the alkali component, such that a concentration of the second component contained in the used liquid is in a range of 0.001 to 2.0 mass %, and a concentration of the alkali component contained in the used liquid is in a range of 0.1 to 2.5 mass %.
Alternatively, it is also preferable that when the organic film is a functional film, the receiving step receives a used liquid containing a third component constituting an organic film of a same type or different type from the functional film as the used liquid; the concentration measuring portion measures concentrations of the third component and an alkali component contained in the used liquid; and the adjusting portion adjusts an alkalinity of the used liquid, based on the actually measured concentration values of the third component and the alkali component, such that the concentration of the third component contained in the used liquid is in the range of 0.001 to 0.5 mass %, and a concentration of the alkali component contained in the used liquid is in the range of 0.05 to 2.4 mass %.
More specifically, it is more preferable to include (e) a pre-treating portion provided between the receiving portion and the adjusting portion, including at least one portion selected from the group consisting of a filtrating portion for filtrating the used liquid; a residual component removing portion for removing the first component (or the second component or the third component) that remains in the used liquid; and a metal component removing portion for removing a metal component contained in the used liquid.
It is further preferable that the filtrating portion filtrates the used liquid into a permeated liquid and an unpermeated liquid by cross flow filtration, and the treating liquid supplying equipment includes (f) an unpermeated liquid transferring portion connected to the filtrating portion and the adjusting portion, for transferring the unpermeated liquid from the filtrating portion to the adjusting portion. It is even more preferable to include (g) a post-treating portion provided between the adjusting portion and the supplying portion, including a particle removing portion for removing a particle component contained in the regenerated liquid.
In addition, it is useful to include (h) a leveling portion connected to the adjusting portion, to which the regenerated liquid is spontaneously transferred from the adjusting portion by water head pressure difference, for leveling the concentrations of the first component (or the second component or the third component) and the alkali component contained in the regenerated liquid. This makes it easy to supply the regenerated liquid to serve as the alkali-based treating liquid to the treating portion of the organic film consecutively, and the concentrations of the first component (or the second component or the third component) and the alkali component contained in the regenerated liquid supplied can be maintained more stably than being supplied by a batch system.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.